Max von fxestbe



PATENT OFFICE.

MAX VON FORSTER, OF BERLIN, IBUSSIA, GERMANY.

COATING GUN-COTTON.

SPECIFICATION forming part of Letters Patent No. 315,357, dated April 7, 1885.

Application filed December 11, 1884. (No specimens.) Patented in Germany March 9, 1883, No. 23,808, and July 31, 1883, No. 26,014; in Italy August 20, 1883, XVII, 15,774, and in Austria-Hungary December 13, 1883, No. 33 and No. 2,486.

To all whmn it may concern.-

Be it known that I, MAX VON FoRs'rER, a subject of the King of Prussia, residing at Berlin, in the Kingdom of Prussia and German Empire, have invented new and useful Improvements in Treating Gun Cotton, of which the following is a specification.

This invention relates to a new product, which consists of an article made of trinitrocellulose organ-cotton provided with a coating of the same substance. Gun-cotton or trinitrocellulose can be readily distinguished from collodion cotton (which term com prises the lesshighly-nitrated compounds) by its insolubility in alcohol and ether, or in Woodalcohol alone or mixed with ether. It is soluble in ethylic acetate, and it has the formula (J,H,(NO,),,O (See Watts Dictionary of Chemistry, 1877, Vol; IV, page 7 77, and Fownes Manual of Chemistry, Philadelphia, 1878, page 634, under the articles in said works on pyroxyline.) This trinitro-cellulose orgun-cotton is the only one of thenitrated compounds of cotton adapted for gunnery.

I'n carrying out my invention I select guncotton which is free from all admixture of any other substance, or of any of the lower substitution compounds which are soluble in mixtures of alcohol and ether, or in ether or in glacial acetic acid. This gun-cotton I compress into therequired form-si1ch as a disk or pellet-and these disks .or pellets I treat with a solvent -such as ethylic acetate. As soon as the solvent has penetrated intothe disk or pellet to a certain depth the article is removed and dried, and upon the evaporation of the, solvent a compact coating of gun-cotton is formed which protects the article,when

it is dry, against crumblingto pieces, and also against the influence of moisture and the'formation of fungus, or if the coating is formed on the surface of a wet. article it (the coating) retards the evaporation of the moisture present. By this treatment I obtain a product which retains all the qualities of gun-cotton, since no foreign substance is introduced which would be liable to change the combustion and behavior of the trinitro-cellulose or gun-cotton, while my product is protected against the influence of moisture and the formation of fungus, as already stated.

I am aware that in Abels British Patent No.1,102 of 1863, it is stated thata1c0hol,winespirit, wood-spirit, and ether are, used to ob tain a binding material in the interior of the gun-cotton of which the pulp or the pieces are composed but it should be noticed that trinitro-cellulose or the most explosive kind of pyroxyline is not soluble in alcohol, wiue= spirit,wood-spirit,or ether, and consequently Abels invention is applicable only to lesshighly-'nitraied compounds of pyroxyline which are soluble in alcohol,wine-spirit,woodspirit, or ether, otherwise no binding efl'ect canbe produced. This is apparent from Abels specification, in which he mentions soluble and f insoluble gun'- cotton. The soluble gun-cotton of Abel designates collodion cotton or a less highly-nitrated compound, while the insoluble gun-cotton is meant to designate trinitro-cellulose, which alone of these compounds is serviceable in gunnery. The result pro duced by the admixture of collodion cotton to the trinitro-cellulose' is an article the action of which differs widely from my product, which is composed of pure trinitro-cellulose without the admixture of any foreign substance. The same remarks apply to the British Patent No; 4,917 of 1882, which sets forth the process of compressing gun-cotton and dipping it into a mixture of collodion and bisulphite of car bon to form a hard coating,which protects the gun-cotton againstthe influences of damp and the weath er.-

I am also aware'of the British Patent No. 3,127 of 1867, which describes a processof impregnating gun-cotton with a solution of either india-rubber, gutta-percha, or balata I diluted either with their own solvents or with other light spiritssuch as benzole or paraflinia-spirit-which solution on drying leaves a uniform deposit upon and between the par- Inall these processes extraneous-matter is ticles of gun-cotton, the object,as set forth,being to render the gun-cottonmore or less wa- 'ter-proof and retardthe explosive properties:

added to the trinitro cellulose, and consequently the properties of the finished product difier essentially from those of pure trinitro- 2. As a new product, compressed pure tricellulose, while my product retains all the nitro-oellulose having a coating of the same properties of pure trinitro-cellulose. mixture, substantially as described.

What I claim as new, and desire to secure In testimony whereof I have hereunto set my 5 by Letters Patent, is-- hand and seal in the presence of two subseribr 5 1. The process of applying a coating to triing witnesses. nitro-oellulose or pure gun-cotton, -consisting MAX VON FORSTER. [L. s] in treating the latter with a solvent which will Witnesses: dissolve part of the gun-cotton and leave a G. P. MICHEL, 3 hard film when dry,substantially as described. JOHN H. SOHNABEL. 

